SUBTRACTION OF THE TELLURIC INDUCTIVE COMPONENT FROM VAN MEASUREMENTS

In order to understand the role of electrical properties in the vicinity of VAN stations, that have already been found to be appropriate for the collection of seismic electric signals (SES), a magnetotelluric (MT) investigation was carried out over of the entire VAN network. We present preliminary MT results for two stations of the VAN telemetric network in continental Greece. A procedure was developed by which a ''real time'' subtraction of the telluric inductive component from the electric measurements can be made. The resulting real time recording of the residual electric field allows a better identification of the SES. Such an example is presented for an SES that preceded a 5.5 magnitude earthquake in western Greece.